Hydrocracking with low hydrogen consumption



United States Patent 3,392,109 HYDROCRACKING WITH LOW HYDROGEN CONSUIVIPTION Harold Beuther, Gibsonia, and Bruce K. Schmid, Mc-

Candless Township, Allegheny County, Pa., assignors to Gulf Research & Development Company, Pittsburgh, Pa, a corporation of Delaware No Drawing. Continuation-impart of application Ser. No. 354,148, Mar. 23, 1964. This application Dec. 6, 1966, Ser. No. 599,375

Claims. (Cl. 208-112) ABSTRACT OF THE DISCLOSURE Catalytic hydrocracking of hydrocarbon oils to produce gasoline and higher boiling products of high aromatics content is achieved with low hydrogen consumption by the concurrent use of (a) a low nitrogen feed stock containing a substantial proportion of hydrocarbon components containing at least one saturated ring to act as a hydrogen source, (b) an alumina base composite hydrogenation catalyst having most of its pore volume in pores havinga radius less than 70 A., and (c) a relatively high reaction temperature coupled with a relatively low reaction pressure.

This is a continuation-in-part of application, Ser. No. 354,148, filed Mar. 23, 1964, now abandoned.

This invention relates to improvements in the art of catalytic hydrogenative cracking with metal or oxide catalyst, and particularly to a hydrocracking process for forming gasoline in which process consumption of hydrogen is minimized.

It has previously been proposed to convert hydrocarbon fractions boiling in the furnace oil range, i.e., about 400 to 650 F., into lower boiling hydrocarbons, especially gasoline, by hydrocracking. This procedure involved contacting the hydrocarbon with hydrogen at hydrocracking temperatures and pressures in the presence of a two component catalyst, i.e., one component having hydrogenation activity and the other component having cracking activity. Hydrogenating components may comprise nickel, nickel sulfide, platinum, palladium, etc. The cracking component is usually a silica-alumina cracking catalyst and usually consitutes the carrier for the hydrogenating component. While previously proposed hydrocracking procedures have been effective to upgrade many furnace oil range feed stocks by production of lower boiling components in good yields, such procedures heretofore have been characterized consistently by high hydrogen consumption, and by formation of naphtha and heavier products low in aromatic content. Naphtha range products of low aromatics content are characterized by correspondingly low octane ratings. Previously proposed procedures also have not been fully satisfactory for upgrading highly aromatic, refractory furnace oil range stocks such as catalytically cracked stocks. Although the relatively high hydrogen consumption encountered in previously proposed hydrocracking procedures can be tolerated in refineries where surplus hydrogen is available at low cost from processes such as naphtha reforming, these previously proposed hydrocracking procedures are less economically attractive in hydrogen-deficient locations where installation of such processes would also entail installation "ice of an auxiliary hydrogen manufacturing plant. This is especially true in locations where available feed stocks for hydrocracking are chiefly the high hydrogen-consuming, aromatic, refractory stocks of the kind referred to above.

It is recognized that certain previously issued patents, for example, US. Patents Nos. 3,172,833, 3,184,404, and 3,222,273 contain disclosures which may include within their broadest limits one or more of the feed stocks, catalysts, and process conditions that are characteristic of the present invention, but it is apparent from the context of these disclosures and from the specific embodiments and results described that the particular combinations of features of the present invention were not contemplated.

The present invention relates to a novel hydrocracking process characterized by exceptionally low hydrogen consumption, or even at times, by a net hydrogen yield, by production of naphtha range and heavier products of unusually high aromatics content, and by the ability effectively to upgrade refractory, highly aromatic fed stocks. The process of this invention includes a combination of steps, including hydrocracking hydrocarbon feed stocks, including highly aromatic stocks, i.e., feed stocks containing not more than about percent and preferably not more than about 70 percent aromatics, having a boiling range in the range of about 400 to 650 F., having a nitrogen content insufiicient to rapidly deactivate the hydrocracking catalyst, i.e., at least below 25 p.p.m., and preferably below 10 p.p.m., and most advantageously as near zero as possible, and containing at least 30 percent hydrocarbon components that contain at least one saturated ring, by contacting the same with hydrogen in the presence of a composite catalyst comprising a hydrogenating component and an activated alumina which has no more than 20 percent and advantageously no more than 10 percent pores having a radius greater than 70 Angstrom units. Preferably, the alumina component also will contain less than 0.05 percent sodium, less than 0.05 percent sulfur as sulfates, and will have a surface area above about 100 square meters per gram. The composite catalyst may be promoted with halogen such as fluorine, up to about 2 to 3 percent by weight. Examples of suitable hydrogenating components are nickel, cobalt,

molybdenum and tungsten, either as such or in oxided or sulfided form, or combinations of two or more of these metals or components. Other hydrogenating components that can be used include other metals of Group VIa and Group VIII, e.g., platinum and palladium, and compounds and combinations thereof. The process of this invention is carried out at a temperature in the range of about 775 to 1000 F., preferably about 850 to 950 F., at a hydrogen partial pressure in the range of about 300 and 1000 p.s.i.g., preferably about 400 to 700 p.s.i.g., at a space velocity between about 0.5 and 4.0, preferably about 1 to 2 liquid volumes of feed per hour per volume of catalyst. The temperature and space velocity are selected to result in between about 40 and percent conversion to materials boiling below 400 F. In an especially advantageous embodiment, the composite catalyst is pretreated after each regeneration and prior to each onstream period by contact with a mixture of hydrogen and about 1 to 20 percent hydrogen sulfide and a mixture of hydrogen and about the same amount of ammonia as hydrogen sulfide. This pretreatment is effected at temperatures of as low as about 400 F. up to about 900 F., but preferably no greater than the initial onstream temperature. As indicated, in accordance with the abovedescribed procedure, there is obtained exceptionally low hydrogen consumption, i.e., less than 650 and preferably less than 500 standard cubic feet per barrel of oil and unusually high aromatics content and octane number in the product boiling below 400 F., and unusually high aromatics content in the product boiling above 400 F.

The catalyst support for the hydrogenating component may be any activated alumina which has no more than about percent, desirably no more than 10 percent, of its pore volume in pores having a radius greater than 70 Angstrom units. This pore size distribution should also exist in the composite catalyst after the hydrogenating component has been deposited thereon. The alumina supports disclosed herein are also generally characterized by a surface area greater than 100 square meters per gram, and a sodium content less than about 0.05 percent sodium and 0.05 percent sulfur as sulfates, but the advantages of this invention do not appear to be directly attributable to these properties. Aluminas of the kind whose use is included by this invention can be obtained commercially, an example being the H-42 and H44 Aluminas manufactured by the Aluminum Company of America. Alternatively, the herein-disclosed aluminas can be prepared from the appropriate raw materials in any convenient way. For example, there can be used aluminas prepared in accordance with the procedures described in U.S. Patent Nos. 3,188,174, 3,151,939 and 3,151,940.

The activated alumina carrier having the herein-disclosed pore size distribution is composited with a hydrogenating component of the kind customarily used in a hydrocracking catalyst such as Group VI and/ or Group VIII base and noble metals or oxides or sulfides. Specific examples are nickel, cobalt, platinum, palladium, nickel sulfide, tungsten sulfide, etc., a mixture of nickel and tungsten sulfides being preferred. Any conventional procedures for compositing porous carriers to form a multicomponent catalyst may be used. Ordinarily we prefer to impregnate the activated alumina carrier with an aque- Ous solution of a salt of the hydrogenating metal followed by drying and calcining. If two hydrogenating components are used, such as a nickel-tungsten mixture, it is advantageous to first deposit one of the components, such as tungsten, followed by drying and calcining and then impregnate with an aqueous salt of the other component, such as nickel, followed by a second drying and calcining.

Other known procedures, such as simultaneous impregna- 1 tion of both metal components, may be employed. See for instance U.S. Patent No. 2,703,789, McKinley and Pardee. Between about 0.5 and 35 percent by weight of hydrogenating component may be incorporated into the alumina support. In the case of a nickel tungsten catalyst, between about 3 percent and percent by weight of tungsten and 0.5 and 10 percent nickel may be employed. A catalyst containing about 3 percent nickel and 3 percent tungsten is especially advantageous since it results in superior retention of aromatic hydrocarbons in the product. Although we have referred to the metal components as sulfides or in sulfided form, this is not to be taken to indicate that they are necessarily conventional sulfides, since the sulfur component may be present in other chemical combinations, for example, nickel thiotungstate, etc.

The importance of the herein-disclosed catalyst pore .size distribution for purposes of the present invention has been demonstrated experimentally by hydrocracking a highly aromatic, refractory, fluid catalytically cracked furnace oil distillate of the class disclosed herein in accordance with the conditions of the present invention using catalysts prepared from aluminas having a variety of pore size distributions. This feed stock had been bydrodenitrogenized in conventional fashion "to a nitrogen content of less than 1 p.p.m. In each instance, the catalytic hydrogenating component was sulfided nickel-tungsten. In each run, hydrocracking was carried out at 900 F., 500 p.s.i.g., hydrogen partial pressure, at a space velocity of 2.0 liquid volumes of feed per hour per volume of catalyst, and at a hydrogen: oil ratio of 10,000 standard cubic feet of hydrogen per barrel of oil. Representative results are indicated in Table 1 below, wherein Alumina Support 1 was an activated alumina prepared by drying and calcining an aluminum hydroxide containing 1.2 to 2.6 mols of water of hydration, as described herein, Alumina Support 2 was a commercial, activated alumina, Alumina Support 3 was a commercial, activated eta alumina catalyst, and Alumina Support4 was .a commercial, activated alumina thought to be a gamma alumina, having a density of 1.285 and a surface are of about 111.6 square meters per gram.

From a comparison of the foregoing results, it will be seen that the activated alumina catalyst supports of Runs 1 and 2, which had a pore size distribution in the herein-disclosed ranges, exhibited a marked superiority in the process of this invention with respect to percent material converted to lower boiling hydrocarbons.

When a catalyst containing a sulfided hydrogenating component is to be employed and such component is not initially deposited in sulfided form, the catalyst is then treated with a sulfiding material such as hydrogen sulfide to form the metal sulfides. This is carried out advantageously by treating with a mixture of hydrogen and hydrogen sulfide containing up to about 20 percent hydrogen sulfide, at a temperature between about 400 and 900 F. As indicated, especially advantageous results as regards conversion are obtained when sulfiding is combined with treatment as similar conditions with a mixture of hydrogen and ammonia in about the same proportions as the hydrogen sulfide. The combined pretreatment can be carried out simultaneously or in separate steps in either order, as preferred. In each case, pretreating in single or consecutive steps at temperatures not exceeding the on-stream temperatures to be used in the hydrocracking reaction, and at space velocities about 500 to about 5000 volumes of gas per hour per volume of catalyst, for at least about /2 hour up to several hours.

The advantages of the above-indicated combination pretreatment have been demonstrated experimentally by treatment in accordance with the present invention, of a refractory, highly aromatic, fluid catalytically cracked furnace oil of the kind disclosed herein that had been hydrodenitrogenized in conventional manner to a nitrogen content of less than 1 p.p.m. The catalyst employed in the series of runs indicated comprised 1 percent platinum deposited on an alumina base of the kind described herein prepared by drying and calcining an aluminum hydroxide containing 1.2 to 2.6 mols of water of hydration as described herein. Each of the catalyst pretreating steps were carried out for one hour at 700 F. and at 500 p.s.i.g., and at a space velocity of 3470 volumes of gas per hour per volume of catalyst. Hydrocracking with the pretreated catalysts was carried out for periods of from 8 to 40 hours at 900 F., at a hydrogen partial pressure of 500 p.s.i.g., at a space velocity of 2.0 liquid volumes of feed per hour per volume ofcatalyst, and at hydrogenzoil ratios of 10,000 standard cubic feet of hydrogen perbarrel of oil. The results obtained in these runs Were as indicated in the following table:

TABLE 2Continued Catalyst Platinum Alumina Pretreatment 100% H28, 90%

Comparison of the results shown in Table 2 shows that markedly improved yields of naptha boiling range material are obtainable by the use of the herein-disclosed special pretreating process. Excellent results are also obtained with respect to yields of naphtha range product by the use of the foregoing pretreating process in conjunction With a nickel-tungsten alumina catalyst of the class disclosed herein.

The presence of a halogen and/ or silica in the hereindisclosed catalysts in many cases has a beneficial effect. Therefore, our invention includes the presence of either or both of these materials. However, it is not limited to the presence or use of these materials. Fluorine and/or its compounds are preferred halogens and may be incorporated by treatment of the activated alumina carrier with a fluorine compound such as ammonium fluoride, hydrofluoric acid, fiuosilicic acid, etc. A preferred method of incorporating fluorine is to treat the alumina carrier prepared as described above with a mixture of ammonium fluoride and ammonia. The silica component may be incorporated by treatment with siliceous compounds such as tetra-ethylorthosilicate, sodium silicate or silicon tetrachloride. After treatment with one of these silicon compounds, the alumina carrier is calcined to convert the compound into silica. In the event that sodium silicate is employed, it is necessary to thoroughly remove the sodium by water washing. Incorporation of between about 0.1 percent and 5 percent halogen and between about 1 percent and percent silica is advantageous in most cases.

Our process is generally applicable to the treatment of feed stocks having a boiling range predominantly in the range of about 400 and 650 F. provided that it has a nitrogen content insufficient to rapidly deactivate the hydrocracking catalyst and provided that it contains at least about percent and preferably at least about percent of hydrocarbons having at least one saturated ring, and no more than about 80 percent, preferably no more than about percent aromatics. The indicated content of hydrocarbons containing saturated rings is important, since the herein-disclosed catalysts selectively ooact with such hydrocarbons to provide an internal source of hydrogen in the process. Examples of suitable feed stocks are straight run light furnace oil, full range straight run furnace oil and straight run light gas oil. However, the invention is particularly useful in the treatment of refractory, cracked hydrocarbons boiling in the ranges specified, which feed stocks are difiicult to crack by any process. An especially high octane product with very low hydrogen consumption is obtainable when the feed stock is a light, catalytically cracked furnace oil, i.e., boiling in the 400 to 500 F. range. Thus, products having about 5 to 6 higher leaded Research octane numbers are obtainable concurrently with a net hydrogen yield when using such feeds as compared with similar treatment of a full range catalytically cracked furnace oil.

The importance of the content in the feed of hydrocarbons containing saturated rings has been shown by a comparison of hydrocracking runs carried out as described herein on feeds containing varying amounts of hydrocarbons having at least one saturated ring. The catalyst in these runs was a sulfided nickel-tungsten on an activated alumina having the pore size distribution indicated herein and prepared by drying and calcining an aluminum hydroxide containing 1.2 to 2.6 mols of water of hydration. The runs were carried out at 900 F., 500 p.s.i.g. hydrogen partial pressure, at a space velocity of 1.0 volume of liquid feed per hour per volume of catalyst, and

6 at a hydrogen to oil ratio of 10,000 s.c.f./bbl. The re sults of these runs were as follows:

TABLE 3 Feed Stock A B Properties;

Gravity: API 27.8 15.6 Hydrocarbon Type; percent by Vol.:

Aromatics 64. 6 91. 8 OlefinS 1. 7 1.2 saturates 33. 7 7. 0 Hydrocarbons containing at least one saturated ring: percent by Vol 58 25 Nitrogen: P.p.n1 1 1 Initial Boiling Point, F 400 400 Conversion: percent by Vo B low 400 F 42 4 From the foregoing comparison it will be seen that the herein-described process produces greatly superior results with feed stocks having an aromatics content and a content of hydrocarbons having at least one saturated ring within the ranges disclosed above.

When the feed stock is a straight run material, the nitrogen content can be relatively high, up to 25 or even 50 ppm, as straight run materials are relatively easily converted. However, when the feed is a refractory material, such as a highly aromatic cracked cycle stock, the

nitrogen content of the feed should be low, at least 'below 25 ppm, preferably below 10 ppm. and most advantageously as near zero as possible, for example, less. than 3 ppm. or even less than 1 ppm. nitrogen. Since cracked cycle stocks normally are high in nitrogen content, for example, on the order of 200 ppm. nitrogen or more, these and other objectionably high nitrogen feed stocks should be denitrogenized before treating in accordance with this invention.

The hydrocarbon to be hydrocracked is contacted with the above-described catalyst in the presence of hydrogen under hydrocracking conditions which result in dehydro genation and concomitant formation of aromatic hydrocarbons. A hydrogen partial pressure of between about 100 and 1000 p.s.i., and preferably between 400 ond 600 p.s.i., a temperature between about 775 and 1000 F. and preferably between 850 and 900 F., and a space velocity between about 0.5 and 3.0 are used to obtain this result. As those skilled in the art will recognize, the above-indicated conditions represent a combination of unusually low pressures and high temperatures. This combination of conditions is characteristic of the process. By way of illustration, it has been calculated that in a given embodiment of the invention, an increase in hydrogen pressure of from 500 p.s.i.g. to 1500 p.s.i.g. would increase the hydrogen consumed from minus 50 s.c.f./ bbl. of feed to more than 1000 s.c. f./bbl. of feed. The amount of conversion is controlled to result in between about 40 and percent of feed into gasoline boiling between 400 and F. The maximum practical conversion will depend primarily upon the aromatic content of the product. This relationship is a result of the fact that at least part of the hydrogen used in hydrocracking must come from the feed stocks. Hence, feed stocks of relatively low aromatic and high naphthene content can be hydrocracked very extensively using only the hydrogen available in the feed. For such feed stocks, as for example a typical straight run furnace oil, the conversion can be as high as 90 percent. For feed stock containing a high concentration of aromatics, however, the maximum practical conversion is substantially lower. The most difficult feed stock to hydrocrack by this method is one that is composed predominantly of aromatics, where the available hydrogen is in the form of aromatic-naphthenic bicyclic compounds, such as tetralin or indanes. For such feed stocks, the maximum practical conversion is limited to about 60 percent by volume.

At the pressures, temperatures and conversions disclosed above, the hydrogen consumption will 'be low and on the order of no more than about 650 and preferably no more than about 300 cubic feet per barrel of feed. As

a matter of fact, a net hydrogen production is obtainable, as this result actually has been achieved. The conversion is controlled in known manner by using a temperature and a space velocity within the ranges specified to obtain the desired conversion. Thus, with a fixed space velocity, increasing the temperature will increase conversion. With a given temperature, decreasing space velocity will increase conversion. Hydrogen is employed in amounts between about 200 and 25,000 s.c.f./bbl. of feed. It is common in the hydrocracking art to initially use a low temperature and increase the temperature to maintain conversion in the desired range as the catalyst becomes deactivated. This expedient is advantageously employed in our process. However, the temperatures used should be within the ranges specified above.

The catalyst used in our process can be regenerated by combustion in the usual fashion and such regeneration will result in elimination of harmful compounds such as coke and nitrogen compounds and the poisoning effect thereof. During regeneration of the catalyst, a temperature of 800 to 1200 F. may be used.

In a specific embodiment of the invention, a hydrodenitrogenized, light, fluid catalytically cracked furnace oil distillate was hydrocracked in accordance with the present invention at 850 F., at a hydrogen partial pressure of 500 p.s.i.g., at a space velocity of 1.0 liquid volume of feed per hour per volume of catalyst, and at a hydrogen to oil ratio of 10,000 s.c.f./bbl. of oil. The catalyst was 6 percent nickel, 19 percent tungsten on an activated alumina having 7.6 percent of its pores of a radius greater than 70 Angstrom units, prepared by drying and calcining an aluminum hydroxide containing 1.2 to 2.6 mols of water of hydration as described herein. The catalyst was pretreated at 700 F. and at 500 p.s.i.g. for three hours with a gaseous mixture containing percent hydrogen sulfide, 2 percent ammonia and 88 percent hydrogen. The feed stock had the following properties:

Feed stock Light FCC (Descriptionlnspections): furnace oil Gravity, API 27.8 Sulfur, p.p.m 2 Nitrogen, p.p.m. 1 Aromatics, percent by vol 64.6

Hydrocarbons having at least one saturated ring, percent 58 AST=M distillation, percent The results of the foregoing run are presented in the table below:

TABLE 4 Yields (Percent by vol. of feed):

From the foregoing results it will be seen that good yields of relatively high octane gasoline with extraordinarily low hydrogen consumption, can be produced from normally refractory, high hydrogen-consuming, aromatic feeds, in accordance with the process of this invention. In addition to high octane gasoline, this process produces a very unusual hydrocarbon fraction boiling above 400 F. This fraction is extremely low in nitrogen 1 p.p.m.), sulfur 10 p.p.m.) and olefins 1%), and is unusually high in aromatics content. Thus, a 400 F.+ product containing more than 90 percent aromatics was obtained, as shown. The low level of impurities and the high concentration of aromatics makes this product potentially valuable for specialty uses, i.e., as an aromatic solvent, as a source of chemicals, or even for direct use as a chemical intermediate. Such a product is usually obtainable only by means of an expensive solvent extraction step, but can be readily produced by this process.

The invention is not limited to the foregoing embodiment, as good results are also obtainable utilizing other catalysts of the class disclosed herein, other conditions within the ranges disclosed, and with other feed stocks of the kind described.

We claim:

1. A process for hydrocracking a hydrocarbon fraction that contains not more than about percent aromatic hydrocarbons and at least 30 percent hydrocarbon components containing at least one saturated ring, that has a boiling range predominantly in the range of about 400 to 650 F. and that has a nitrogen content insufficient to cause rapid deactivation of catalysts and less than 25 p.p.m., which comprises contacting said hydrocarbon fraction with hydrogen at a hydrogen partial pressure in the range of about 300 to 1000 p.s.i.g. in the presence of a presulfided hydrogenation catalyst composited with an activated alumina that does not have more than about 20 percent of its pore volume in pores having a radius of more than 70 Angstrom units, said contacting being carried out at a temperature in the range of about 775 to 1000 F. and a space velocity in the range of 0.5 to 4.0 volumes of liquid per hour per volume of catalyst, the combination of temperature and pressure being selected within the ranges indicated to form about 40 to percent hydrocarbons boiling below about 400 F. that are relatively high in aromatics content and octane number and a product boiling above 400 F. that has a greater aromatics content than the hydrocarbon fraction feed stock, with a hydrogen consumption of not more than about 650 standard cubic feet per barrel of said feed stock.

2. The process of claim 1 in which said activated alumina does not have more than about 10 percent of its pore volume in pores having a radius of more than 70 Angstrom units.

3. The process for hydrocracking a cracked furnace oil distillate that contains not more than about 70 percent aromatic hydrocarbons and at least 40 percent hydrocarbon components containing at least one saturated ring, that has a boiling range predominantly in the range of about 400 to 650 F. and that has a nitrogen content less than 3 parts per million, which comprises contacting said cracked furnace oil distillate with hydrogen at a hydrogen partial pressure in the range of about 300 to 1000 p.s.i.g. in the presence of a presulfide hydrogenation catalyst composited with an activated alumina that does not have more than about 20 percent of its pore volume in pores having a radius of more than 70 Angstrom units, said contacting being carried out at a temperature in the range of about 775 to 1000 F. and a space velocity in the range of 0.5 to 4.0 volumes of liquid per hour per volume of catalyst, the combination of temperature and pressure being selected within the ranges indicated, to form about 40 to 60 percent hydrocarbons boiling below about 400 F. that are relatively high in aromatics content and octane number and a product boiling above 400 F. that has a greater aromatics content than the cracked furnace oil distillate feed stock, with a hydrogen consumption of not more than 300 standard cubic feet per barrel of said feed stock.

4. The process of claim 3 where said cracked furnace oil distillate is a light furnace oil distillate boiling predominantly in the range of about 400 to 500 F.

5. A process for hydrocracking a hydrocarbon fraction that contains not more than about 80 percent aromatic hydrocarbons and at least 30 percent hydrocarbon components containing at least one saturated ring, that has a boiling range predominantly in the range of about 400 to 650 F. and that has a nitrogen content insufficient to cause rapid deactivation of catalysts and less than p.p.rn. which comprises contacting said hydrocarbon fraction with hydrogen at a hydrogen partial pressure in the range of about 400 to 700 p.s.i.g. in the presence of a presulfided hydrogenation catalyst composited with an activated alumina that does not have more than about 20 percent of its pore volume in pores having a radius of more than 70 Angstrom units, said contacting being carried out at a temperature in the range of about 850 to 950 F. and a space velocity in the range of about 1 to 2 volumes of liquid per hour per volume of catalyst, the combination of temperature and pressure being selected within the ranges indicated to form about 40 to 90 percent hydrocarbons boiling below about 400 F. that are relatively high in aromatics content and octane number and a product boiling above 400 F. that has a greater aromatics content than the hydrocarbon fraction feed stock, with a hydrogen consumption of not more than about 650 standard cubic feet per barrel of said feed stock.

6. The process for hydrocracking a hydrocarbon fraction that contains not more than about 80 percent aromatic hydrocarbons and at least '30 percent hydrocarbon components containing at least one saturated ring, that has a boiling range predominantly in the range of about 400 to 650 F. and that has a nitrogen content insufficient to cause rapid deactivation of catalysts and less than 10 ppm, which comprises contacting said hydrocarbon fraction with hydrogen at a hydrogen partial pressure in the range of about 300 to 1000 p.s.i.g. in the presence of a hydrogenation catalyst composited with an activated alumina that does not have more than about 20 percent of its pore volume in pores having a radius of 70 Angstrom units, said catalyst having been pretreated at a temperature and pressure within the ranges utilized for the hydrocracking reaction, with hydrogen and l to 20 percent of ammonia and hydrogen sulfide, said contacting being carried out at a temperature in the range of about 775 to 1000 F. and a space velocity in the range of about 0.5 to 4.0 volumes of liquid per hour per volume of catalyst, the combination of temperature and pressure being selected Within the ranges indicated to form about 40 to 90 percent hydrocarbons boiling below about 400 F. that are relatively high in aromatics content and octane number and a product boiling above 400 F. that has a greater aromatics content than the hydrocarbon fraction feed stock, with a hydrogen consumption of not more than 650 standard cubic feet per barrel of said feed stock.

7. The process of claim 6 where the activated alumina does not have more than about 10 percent of its pore volume in pores having a radius of more than 70 Angstrom units.

8. The process for hydroerackrng a cracked furnace oil distillate that contains not more than about 70 percent aromatic hydrocarbons and at least 40 percent hydrocarbon components containing at least one saturated ring, that has a boiling range predominantly in the range of about 400 to 650 F. and that has a nitrogen content less than 3 parts per million, which comprises contacting said hydrocarbon fraction with hydrogen at a hydrogen partial pressure in the range of about 300 to 1000 p.s.i.g. in the presence of a hydrogenation catalyst composited with an activated alumina that does not have more than about 20 percent of its pore volume in pores having a radius of 70 Angstrom units, said catalyst having been pretreated at a temperature and pressure within the ranges utilized for the hydrocracking reaction, with hydrogen and l to 20 percent ammonia and hydrogen sulfide, said contacting being carried out at a temperature in the range of about 775 to 1000 F. and a space velocity in the range of about 0.5 to 4.0 volumes of liquid per hour per volume of catalyst, the combination of temperature and pressure being selected within the ranges indicated to form about 40 to percent hydrocarbons boiling below about 400 F. that are relatively high in aromatics content and octane number and a product boiling above 400 F. that has a greater aromatics content than the cracked distillate feed stock, with a hydrogen consumption of not more than 300 standard cubic feet per barrel of said feed stock.

9. The process of claim 8 where said cracked furnace oil distillate is a light furnace oil distillate boiling in the range of about 400 to 500 F.

10. The process of hydrocracking a cracked furnace oil distillate that contains not more than about percent aromatic hydrocarbons and at least 40 percent hydrocarbon components containing at least one saturated ring, that has a boiling range predominantly in the range of about 400 to 650 F. and that has a nitrogen content less than 3 ppm, which comprises contacting said cracked furnace oil distillate with hydrogen at a partial pressure in the range of about 400 to 700 p.s.i.g. in the presence of a presulfided hydrogenation catalyst com posited with an activated alumina that does not have more than about 10 percent of its pore volume in pores having a radius of more than 70 Angstrom units, said contacting being carried out at a temperature in the range of about 850 to 950 F. and a space velocity in the range of about 1 to 2 volumes of liquid per hour per volume of catalyst, the combination of temperature and pressure being selected within the ranges indicated to form about 40 to 60 percent hydrocarbons boiling below about 400 F. that are relatively high in aromatics content and octane number and a product boiling above 400 F. that has a greater aromatics content than the cracked furnace oil feed stock, with a hydrogen consumption of not more than 300 standard cubic feet per barrel of feed stock.

References Cited UNITED STATES PATENTS 2,206,729 7/l940 Pier et al. 2081 12 3,067,128 12/1962 Kimberlin et a1 208-138 3,043,770 7/1962 Kant et al 208l12 DELBERT E. GANTZ, Primary Examiner.

A. RIMENS, Assistant Examiner. 

